On the surface, it seems to make sense.
Exercise first thing in the morning on an empty stomach and your body should burn more fat. After all, without food intake for eight to 12 hours, you’re in a fasted state.
With glycogen stores depleted and low morning insulin levels.
Your body has to turn to other energy sources, like fat, to power through your workout.
Fasted cardio is a technique that has been around for years in the bodybuilding community. And one that’s gaining popularity among regular gym goers and even endurance athletes.
But will forgoing your morning oatmeal really lead to a leaner body and better athletic performance?
So how does our body burn fat?
Without going into too much detail, what you need to know is that fat is stored in special tissue called adipose tissue in various locations throughout the body.
In order for fat to be burned (i.e. used for energy), it must first be freed from this adipose tissue.
To do this, fats must first be converted to triglycerides and released into the bloodstream. This process is called lipolysis, which is kick started in the first few minutes of your workout!
Once the fatty acids (triglycerides) are in your bloodstream, they are delivered to your muscles, where they will be oxidised (burned) for energy.
However, the important thing to remember is that fat is a complex structure and oxygen must be present in order for it to be broken down.
If you don’t 100% understand this process, the most important thing to remember is that lipolysis is not the step that determines your body’s fat burning ability. But how much oxygen is available to help break down that fat.
Why Work Out On an Empty Stomach?
The theory behind exercising with an empty stomach is that when you squeeze in a morning cardio session before breakfast, your body burns fat faster.
See, what happens is that glycogen, a type of carbohydrate that our bodies store, “runs out” overnight. When you wake up and hit the gym first thing in the morning, because your body is low on carbs, the idea is that the body will turn to fats next to gain energy.
Things do get tricky because if your body is totally out of glycogen — you had an early dinner.
Got a full night’s rest and maybe snoozed an extra hour or two — the body might skip fat burning and head straight to muscle stores instead, chipping away at body definition.
What are the benefits of exercising on an empty stomach?
Give your hormones a helping hand
As you already know, your body’s hormones have a massive part to play in everything from how you digest your food, to how you build muscle, shed fat and perform in the gym.
Hormones are at the centre of it all. The surprising news is that short periods of fasting, and training on an empty stomach, won’t damage your hormonal activity at all. In fact, it may even optimise it.
Leading to better gym sessions, a leaner body, and a healthier you!
When your body is in a fasted state, with an empty stomach. This prompts a huge array of hormonal activity.
The most significant are better insulin sensitivity and increased growth hormone levels along with improved testosterone in both men and women.
Eating less often encourages the body to release insulin less often, too, and this makes us more sensitive to it when it is released – ultimately making fat loss easier and improving over all health.
Lastly, whilst training fasted doesn’t have a direct impact on testosterone levels, it does create the perfect environment in the body for testosterone to do its thing (which, by the way, including more lean muscle mass, less body fat, higher energy levels, less chance of depression and even minimising heart health problems).
This goes for both men and women.
Boost your exercise and workout performance
Depending on the kind of exercise you do, it could actually make perfect sense to train on an empty stomach. If your morning workout is high intensity cardio (HIIT), long slow cardio (such as powerwalking) or weight training, read on…
Combining these kind of fat loss, muscle gain workouts with short periods of fasting creates an anabolic hormonal environment, encouraging all those positive hormones we just mentioned.
And letting your body release more fat for fuel whilst building serious amounts of lean tissue.
Endurance athletes could consider fasted training, too. Some endurance athletes like to train without eating a solid meal first.
Because training on an empty stomach can improve the way in which our muscles store glycogen (fuel). Ultimately leading to an easier time during your next long race.
So You Want to Fast Before Exercise? Your Action Plan
We know what you’re thinking. “I can’t handle intense exercise without food in my belly!” Firstly, give yourself a little credit!
You’re capable of more than you think with the right frame of mind. Secondly, there are several tips you can follow to help you out with this new approach to eating:
You can consume more than just water
Feel free to quell cravings and get an energy boost with black coffee, plain tea, caffeine pills, Branched Chain Amino Acids, creatine, or any kind of drink or supplement that’s virtually calorie-free.
According to the leading experts on the subject, Brad Pilon and Martin Berkhan, even Diet Coke or sugar-free gum won’t break the fast.
Break your fast whenever you’d like
A lot of people like their first meal right after exercising. Since the fast improves the absorption of the post-workout meal, but it’s actually no big deal if the fast lasts for a while longer.
Even if you exercise in the morning and don’t eat until the evening.
The wave of growth hormone you’ll be riding all day should prevent any muscle loss. However you decide to approach this, your body’s got you covered.
Eat as many meals as you’d like
Note: We didn’t say as many calories as you like. But it’s not necessary to eat many meals throughout the day.
Despite some long-held myths that the body can only absorb a certain amount of protein at a time. We’re completely capable of digesting the day’s intake in one big meal (of course, this doesn’t mean that you need to!).
Studies have shown that doing so results in no strength or muscle loss. And some have even shown that concentrating food intake into one or two meals each day can be a better way to build lean muscle mass.
A lot of protein just takes longer to digest and be utilized, but it still gets digested.
Even after eating a normal-sized meal, amino acids are still being released into the bloodstream and absorbed into the muscles five hours after eating. So play around with the feeding times and styles that work best for you.
The short of it: Metabolism and the digestive system are simply not as temperamental as some might believe.
Disadvantages of Empty Stomach Exercising
Obviously, you cannot train as hard or fast without having more fuel to rely on. It is possible that you could increase your risk of illness or injury by exercising in a depleted state.
Exercise on an empty stomach can increase the production of the stress hormone cortisol. Which can lead to the breakdown of muscle tissue.
To make the best use of the concept of exercising on an empty stomach. You might consider “training low” at times to help your endurance, but switching over to fueled training before a competition or race.